99 - Braille

In the Paris "Institute for the Blind", founded in 1784 as the first such organisation in the world, the young Louis Braille learned to read in a complicated manner using letters in relief, but he himself couldn't write anything.

So he was all the more enthusiastic when one day captain Charles Barbier visited the school to present a kind of "night writing".

In order to give commands to soldiers on dark nights unnoticed by the enemy, he had invented a complicated syllabic writing using dots and lines.

As if possessed, Louis worked for three years to simplify that system and make it useful and practical.

In the year 1825 the basic form of the "writing for the blind", which today bears the name of Braille, was ready. It codifies each letter with just six dots which can be impressed onto paper using a stylus, typewriter or computer, in such a way that they can then be felt by the fingertips.

(from an article in Scienca Revuo)

impress : technical term - give definitive form to an item (usually of metal) by pressing it very forcefully between a die and stamp.